It is known that increased cholesterol values in blood serum of humans represent an increased risk factor for arteriosclerosis and of coronary heart disease.
For this reason, endeavors of the foodstuff industry have the object of distinctly reducing the content of cholesterol and of cholesterol esters in fat-rich foodstuffs of animal origin, an important problem thereby being substantially to maintain the sensory and nutritional-physiological properties of the foodstuffs in the case of such a treatment.
A relatively gentle process for the removal of cholesterol derivatives is the complexing thereof with .beta.-cyclodextrin.
Thus, for example, according to published European Patent Application No. 0,326,469, egg yolk powder, after homogenization thereof with water, is stirred for 5 hours with .beta.-cyclodextrin at 40.degree. C. and the complexes thereby formed are separated by centrifuging.
According to the process of as yet unpublished Federal Republic of Germany Patent Application P No. 39 28 258.9, egg yolk plasma, which has previously been separated from the LDL granula fraction by centrifuging with the help of an emulsion-breaking agents, such as water, is exclusively mixed with .beta.-cyclodextrin. Subsequently, the so-treated egg yolk plasma, after separation thereof from the .beta.-cyclodextrin, is again combined with the LDL granula fraction. In the case of this process, in the separation methods employed (centrifuging, filtration), it cannot be avoided that a part of the dissolved .beta.-cyclodextrin remains behind in the egg yolk or egg yolk plasma.
Cyclodextrins (.alpha., .beta., .gamma.), which are cyclic oligosaccharides consisting of 6 to 8 glucose units, are, according to previously known investigations, toxicologically harmless. Thus, for examples, tests for acute toxicity on mice and rats have, in the case of oral administration, given no indication of a toxic effect. However, in many countries, cyclodextrins have hitherto not been permitted as "food additive".